This proposal requests support for an inverted confocal microscope with UV laser to provide technology which is currently unavailable to and is pivotal for the research effort of ten independent laboratories in the biomedical sciences. Research programs in all ten laboratories are now at a critical phase where long term access to this equipment is essential for further progress. Eight NIH funded users and two other funded groups are identified whose research programs include the following areas of investigation: Cell division, development, structure and function of opioid receptors, long term potentiation, cyclic nucleotide phosphodiesterases, synaptogenesis and synaptic structure, membrane traffic and redistribution of organelles within a cell and the associated changes in second messengers, interactions between calmodulin and neuromodulin, a major constituent of neuronal growth cones, and the expression and localization of voltage-gated ion chamois at the neuromuscular junction and throughout the brain. The broad range of projects proposed by the initial user group is representative of a larger group of potential users of confocal microscopy. The requested instrument would be placed in the established Keck Imaging Facility located on the University of Washington and be made available to other investigators when it is not being used by the core group of researchers. The operation and management of the equipment, the internal advisory committee and institutional support for the confocal microscope are described.